(Book) Software Defined Network_A Comprehensive Approach_2ed_2017

It hides host MAC addresses within the encapsulated frame.

RESTCONF bundles NETCONF requests into easier-to-use REST messages.

Controlling network behavior via policy.

CLI (Command Line Interface) and SNMP (Simple Network Management Protocol).

Their physical counterparts below.

They suffer from birthing pains common to new technologies.

ODL (OpenDaylight) and ONOS.

Open vSwitch (OVS) from Nicira and Indigo from Big Switch.

They allow for quick and automatic responses to changes in the network.

Appropriately interleaving the flows from all applications.

In priority order, with the first matching flow acted upon.

Policies that apply to aggregated flows rather than user-centric policies.

They offer automation and programmability advantages while providing support for network equipment.

Border Gateway Protocol (BGP), BGP Link State (BGP-LS), and Path Computation Element Protocol (PCE-P).

To maintain information about the interconnection details of network devices and end-user devices.

They may not provide an abstract, network-wide view to the programmer.

Applications to have views of the entire network for optimal policy-based forwarding and routing decisions.

It works with legacy switches without requiring upgrades to OpenFlow-enabled switches.

Tunnels interconnecting virtual tunnel endpoints (VTEPs).

SNMP, CLI, or NETCONF.

They inject traffic into the virtual network and receive traffic from it.

End-user devices (like laptops and mobile devices) and network devices (like switches and routers).

HyperText Transfer Protocol (HTTP).

Different ecosystems may grow around each controller, similar to Windows and OSX.

BGP, Cisco CLI, and SNMP.

User application API, Controller API, and Policy API.

They are built primarily from merchant silicon switching chips and a commodity CPU and memory by a low-cost Original Device Manufacturer (ODM).

SDN via APIs and SDN via Hypervisor-Based Overlay Networks.

Virtual network traffic.

Methods may drop, modify, or forward packets, or add, delete, or modify flows.

An open source SDN controller built by a consortium of vendors.

A virtual switch.

By extending support for multiple vendors’ APIs to mask differences.

It can be implemented over a new physical network with simpler switches.

It involves creating virtualized networks above the existing physical network without changing its configuration.

Static flows that are typically the same for every class of discovered network device.

It allows for variable responses based on the current context or user state.

Yes, applications may communicate with devices directly without using a controller.

An intents-based northbound interface (NBI) that supports application communication of network changes.

It can be built from OpenFlow-enabled white box switches at a lower cost than established Network Equipment Manufacturers' switches.

RESTful APIs.

To provide core functionality between raw interfaces and applications.

Additional logic to react to new MAC addresses and update forwarding tables.

Coordination between applications and the lack of a standard northbound API.

It precludes an abstraction layer above.

They do not address existing issues within the physical infrastructure.

The distributed control plane operating on each switch.

A local maintenance of flow statistics that mirrors the flow tables on different switches.

Manual configuration, maintenance, traffic prioritization, and efficiency issues.

It provides SDN functionality in the form of programmability and centralized control, while supporting legacy devices.

Developing reusable applications across a wide range of controllers.

They can be cumbersome and difficult to maintain.

The distinction can become blurred, as both approaches can offer intelligent control of hybrid networks.

They address MAC address explosion, VLAN limitations, and improve agility and automation.

The edge of the virtual network where packets are encapsulated.

Programmability and centralized control.

NOX, Beacon, Floodlight, and Trema.

Cisco (VXLAN), Microsoft (NVGRE), and Nicira (STT).

By implementing functions via pluggable modules.

By providing a centralized platform from which to build SDN applications using the controller's APIs.

Application prioritization and flow handling.

They provide a level of abstraction that shields the SDN application from the complexities of interacting with specific devices.

Building an SDN solution using provided APIs on distributed network devices.

Flows are more fine-grained at the edge and more coarse at the core.

Managing flow entries, configuring flows, balancing traffic, reacting to topology changes, and redirecting traffic for security tasks.

It maintains a view of the entire network, implements policy decisions, controls SDN devices, and provides a northbound API for applications.

Because all traffic is tunneled, allowing for tenant isolation without VLANs.

Maintaining a database of flows and coordinating with devices to ensure synchronization.

To provide a richer set of control points on devices for centralized software manipulation.

To perform specific functions such as load-balancing or firewalling.

Virtual switches interconnected by virtual point-to-point links.

In the language of the controller or alternatives like REST or Python.

The default action is usually to forward the packet to the controller.

Imperative systems require the user to specify how to perform a task, while declarative systems require the user to specify what needs to be accomplished, leaving the method to the system.

Virtual Tunnel Endpoints that encapsulate traffic for virtual networks.

The NBI concept of intents, which raises the API level of abstraction for requests.

Applications can exploit the exposed interfaces, although they may be proprietary.

There may be no controller, requiring direct interaction with each switch.

Applications can read information about nodes and links without performing device and host discovery.

It enables a plug-and-play environment for SDN applications across different controllers.

A method where the entire frame is encapsulated within a unicast IP frame.

Implementing standards mandated by bodies like the ONF.

YANG data definition language.

They often only work with devices from a specific vendor or a small group of compatible vendors.

By providing an enhanced level of APIs on their devices beyond traditional CLI and SNMP.

By registering as a listener for certain events and invoking callback methods when those events occur.

End-user Device Discovery, Network Device Discovery, and Incoming Packet events.

Opportunities for innovation and collaboration among vendors and the open source community.

The resources of the overlay networks.

They address network configuration from a declarative perspective, focusing on policies rather than individual device capabilities.

They may operate in both legacy mode and OpenFlow mode.

To manage how data is forwarded through the network.

It allows applications to interact with the SDN controller, affecting network operations.

They allow virtualized overlay networks to be instantiated across the physical network without concern for the underlying infrastructure.

RESTful APIs.

The standardization of the northbound API.

Primarily OpenFlow implementations.

It simplifies the application development process.

They can be developed to manage hybrid sets of devices.

A Java API and a RESTful API.

Tunneling, which uses encapsulation.

The opportunity for applications to automate processes and provide dynamic control.

It is a device management and configuration protocol favored by vendors and customers.

They require no special firewall configuration as they use a standard TCP port.

Learning switch, router, basic firewall, and simple load balancer.

He states that 'Everything we build will be programmable,' recognizing the impact of SDN.

It supports multiple southbound protocols.

To provide access to network devices in a common and consistent manner.

Events related to individual packets or state changes in the network topology.

Topology information about devices in the network.

An interface between routing protocols and the Routing Information Base (RIB).

Open Network Operating System (ONOS).

OpenFlow, NETCONF, and BGP-LS/PCE-P.

It is crucial for managing network traffic effectively.

The current physical network and its configurations.

1. Programmatic, asynchronous interface for atomic operations. 2. Access to structured routing information. 3. Subscription to filterable event notifications. 4. Extensibility with standard data models.

To move 75% of their critical future functions to a new software-defined architecture.

Experience with a wider array of applications and heterogeneous equipment types.

To provide a level of abstraction between devices and applications.

It allows applications to communicate with SDN devices without knowing the nuances of those devices.

It is optional and adds little or no value to the communication between the application and device.

The ability to build a virtual network on top of an existing physical one.

The details of the physical network from the devices that connect to the overlays.

They provide additional data that can influence application behavior and responses.

The southbound protocols used; Open SDN uses OpenFlow, while SDN via Controller APIs uses legacy protocols repurposed for SDN functionality.

They help in provisioning, configuration management, and automation for networks.

The ability to control switching decisions through a rich family of applications.

It is the best example of standardization in the southbound interface.

Open SDN refers to the original definition of SDN, emphasizing its architecture and control mechanisms.

They are open protocols for the southbound interface, limited to configuration roles.

The lack of a standard for the controller-to-application interface.

OpenFlow.

It interfaces with SDN devices.